Daf ha-kashrus


Olive Oil by Rabbi Akiva Tendler Playing with Fire – Part III

Playing with Fire – Part III

by Rabbi Yaakov Luban, Executive Rabbinic Coordinator, OU Kosher  NOT SERVED AT A ROYAL TABLE Food that is not fit to be served at a royal dinner[1] may be prepared by a non-Jew. Here, too, the level of appreciation to the cook is minimal since the food is not a prestigious item. Some examples of this group […]


• Daf Notes: Responses to out readers on: HPP (high pressured processing),  Zeiya and Kashering Pipelines. • Lo Basi Ela L’Orer: Rov Tashmisho • Kashrus Alert… • Mazel Tovs • Condolences • EIR/EFR ENHANCEMENTS

CHaNaN Lach B’Lach

by Rabbi Eli Gersten The Mordechai (Chulin 697) writes that we do not say Chaticha na’ases neveila regarding sha’rissurim lach b’lach. Only when a chaticha (solid) absorbs issur, do we say that because of its chashivus, the entire mass is transformed into issur. But if liquid heter and issur are combined, the issur will remain […]

Kashering Pipes Properly

by Rabbi Simcha Smolensky, Senior RFR I’ve thought many times about the fluid dynamic physics of product (i.e., oil, chocolate, anything liquid) as well as water (as is used for kashering) moving through pipes. We typically kasher pipes by pumping boiling water through them. Thinking about the physics of this movement, there are a few […]


• Practical Shemittah • Kashering Pipes Properly • Chanan Lach B’Lach • Kashrus Alert • Kashrus Advisory • Mazel Tov • Condolences

Steam Heating – Lo Basi Ela L’Orer

by Rabbi Eli Gersten Although the term “kli rishon” conjures up in our minds a picture of a pot sitting on a flame, in reality in most modern industrial settings the kli rishon refers to a vessel that is heated by steam. Whether it be through steam jacketed kettles, direct steam injection, or hot air […]

ELUL 5774-TISHREI 5775/ SEPT.- OCT. 2014

• Steam Heating by Rabbi Eli Gersten • A Shemittah Primer by Rabbi Moshe Zywica • Pas Yisroel Products • An Eruv Tavshilin Primer • ASK OU 12 Draws Largest Group • What’s the beracha on… Vegetables and Herbs • What’s the beracha on…  Grains and Grain Products • Kashrus Alerts… Mulberries no Longer Group 1 • Kashrus Advisory • Mazel Tov… […]

Daf Hakashrus Yomim Noraim 5775 – Consumer Edition

• Shofar at the Heat Exchanger, A Story of Mesiras Nefesh for Kashrus • Practical Shemittah


A true-life story of present day Mesiras Nefesh for Kashrus By Rabbi Yitzchok Gallor, RFR, Seattle, Washington On the night of Rosh HaShanah, as you walk home from Shul with your precious children by your side, you reflect upon the tranquility of Yom Tov. You imagine with great anticipation the scene at your home…the L’Shana […]